I posted a link on the "Smartest Corgis Ever" thread in response to your Roll Over question. It's a YouTube video link. I tried it with Charlie and it seems to work pretty well. He was resistant to letting his hind legs go out from under him at first...kind of like you're saying about Gizmo! : )
How hard it would be to be away from your Gizmo. My youngest daughter is in college just about an hour an a half from here and she misses her dogs terribly. Welcome to the group. Your Gizmo is a charmer.